Saturday, 22 December 2012

Angle grinder meltdown

There I was, Saturday morning last weekend, working away with a cup brush in the angle grinder, removing the remainder of the paint and rust from the front valance of the Saloon, when all of all sudden the angle grinder starts to feel very light, the cup brush stops spinning and I hear a noise very similar to a differential stripping! I end up with an angle grinder that still spins its armature up to full speed but has a completely static spindle. The spindle, in fact, had gone completely loose with seemingly no connection to the armature.

It became clear what had happened when I dissembled the angle grinder. The four machine screws that secure the spindle assembly to the gearcase had worked loose. This had allowed the spindle to partly disengage from the pinion stripping the pinion teeth in the process.

It wasn't a particularly cheap angle grinder so I reckoned it was worth saving if at all possible. And after a quick internet search, and £3.50 later (the cost of a replacement pinion), it's working again as of this morning!

I'm wondering if the vibration you often get when working with cup brushes fitted to angle grinders is what caused the screws to loosen? So that I don't get held up again when an angle grinder goes down I've bought a second, cheap (£17) angle grinder as backup. What I'll maybe do is use the cup brushes with the cheap angle grinder and keep the better angle grinder for working with flap discs, grinding or cutting.